Upstash Redis

A Redis counter example that stores a hash of function invocation count per region. Find the code on GitHub.

Redis database setup#

Create a Redis database using the Upstash Console or Upstash CLI.

Select the Global type to minimize the latency from all edge locations. Copy the UPSTASH_REDIS_REST_URL and UPSTASH_REDIS_REST_TOKEN to your .env file.

You'll find them under Details > REST API > .env.

1cp supabase/functions/upstash-redis-counter/.env.example supabase/functions/upstash-redis-counter/.env

Code#

Make sure you have the latest version of the Supabase CLI installed.

Create a new function in your project:

1supabase functions new upstash-redis-counter

And add the code to the index.ts file:

1import { Redis } from 'https://deno.land/x/upstash_redis@v1.19.3/mod.ts'23console.log(`Function "upstash-redis-counter" up and running!`)45Deno.serve(async (_req) => {6  try {7    const redis = new Redis({8      url: Deno.env.get('UPSTASH_REDIS_REST_URL')!,9      token: Deno.env.get('UPSTASH_REDIS_REST_TOKEN')!,10    })1112    const deno_region = Deno.env.get('DENO_REGION')13    if (deno_region) {14      // Increment region counter15      await redis.hincrby('supa-edge-counter', deno_region, 1)16    } else {17      // Increment localhost counter18      await redis.hincrby('supa-edge-counter', 'localhost', 1)19    }2021    // Get all values22    const counterHash: Record<string, number> | null = await redis.hgetall('supa-edge-counter')23    const counters = Object.entries(counterHash!)24      .sort(([, a], [, b]) => b - a) // sort desc25      .reduce((r, [k, v]) => ({ total: r.total + v, regions: { ...r.regions, [k]: v } }), {26        total: 0,27        regions: {},28      })2930    return new Response(JSON.stringify({ counters }), { status: 200 })31  } catch (error) {32    return new Response(JSON.stringify({ error: error.message }), { status: 200 })33  }34})

Run locally#

1supabase start2supabase functions serve --no-verify-jwt --env-file supabase/functions/upstash-redis-counter/.env

Navigate to http://localhost:54321/functions/v1/upstash-redis-counter.

Deploy#

1supabase functions deploy upstash-redis-counter --no-verify-jwt2supabase secrets set --env-file supabase/functions/upstash-redis-counter/.env